Fig. 4

I The distributions of superficial neuromasts on the head and II morphology of saccular otolith in the inner ear among the three Sinocyclocheilus species. The superficial neuromasts after DASPEI staining from the plates I-(a–c), I-(d–f) and I-(g–i) represent Sg, Sr and Sa, respectively. The photos from left to right show the lateral view, dorsal view and ventral view. These figures show that the numbers of neuromasts in the adult fishes decline in the following order: Sg > Sr > Sa. The morphology of the saccular otoliths was reconstructed based on synchrotron X-ray microtomography. The plates II-(a–c), II-(d–f) and II-(g–i) represent Sg, Sr and Sa, respectively. The photos from left to right show the location of saccular otoliths in the inner ear, the dorsal view and ventral view of its morphology. The ventral of saccular otolith in Sa is seriously aberrant, with a deep and expanded central pit, encircled by another lateral sulcus. The degree of corrosion increase is in the following order: Sg < Sr < Sa. Scale bar: 1 mm